How do I take average of lat long data of a NetCDF file? Facing problem!

I am having a NetCDF file with sst variable. I have an array named sstdata which is a 1440x168x289 double. (long x lat x time). I need to take domain average of sstdata so that it only varies with time to get a average plot w.r.t time. I have written the following code:

    k=0;
    for m=drange(1:1440)
    for n=drange(1:168)    
    k=k+sstdata(m,n,:);
    end
    end
    k=k./1440;
    k=k./168;

But I am getting only a 1 x 1 x 289 double which only has NaN and zeros as its values. Is there anything wrong with the code? Please help!

Answer 1

[KSSV]

Read about mean. You read the whole variable of size 1440x168x289 into workspace and use mean. mean accepts dimensions...you have to use mean on third dimension.

sst = ncread(filename,'variable') ;  %read  sst data here 
iwant = mean(sst,3) ;

[Lavnish Gupta]

Actually mean is only averaging along the rows which leaves mean as a 1440 X 1 X 289 double. I want to average along columns also to get a 1x1x289 double.

[KSSV]

That means you want mean of whole matrix at a time step?

[Lavnish Gupta]

Yes! For this I did

iwant=mean(sst,2);
iwant2=mean(iwant,1);

Is this right?

[KSSV]

That's fine....you can use:

iwant = mean(mean(A)) ;